Outside feed stoker



Dec. 27, 1932. A. M. HUNT- OUTSIDE FEED STOKER Filed July 13, 1928 5 Sheets-Sheet l m mm Nm Si n I NV EN TOR. @M7/mf Q LN J NQ ww n.

Dec. 27, 1932. A. M. HUNT OUTSIDE FEED STOKER Filed July l5, 1928 6 Sheets-Sheet 2 INVENTOR ATTORNEYS 3 Sheecs-Sheet4 5 Dec. 27, 1932. A. M; HUNT OUTSIDE FEED sToKEE Filed July 15, 1928 A EN, E E.. j, ,i

EN EN n EN Patented Dec. 27, 1932 narran stains .annnnw ai.

raient ortica or nrrwyo'arr, Y., Assis-nen 'ro 'ri-in s'rennAnn sronnn con; y

EAB-l", -CORPCPJATED, A COR'ERTEON 0F. DELAARE i 'OUTSIDE FEED STOKER epinal-ien ined any 1e,

My present invention relates to mechanical stokerdevices and particularly to such devices employed for boilers of locomotives and the like.

5 The generaly object of the invention is to proride new ancimproved devices lof the character specified. More specifically, one` obiect of the invention is the provision of mechanical means for deliveringby feeding or pushing the coal or other materialas it rises outside the boiler, directly into or towards the boiler.`

To the above and other ends which will heren after appear, my invention consists in theV features of construction, combinations of devices and arrangements of parts hereinafter described and particularly pointed out in the claims.

In practice it has been found that there is atendency on the part of the fuel or coal to pack or jam at certain paris of the conduit. The coal; except for certain varieties under a. carefully adjusted water content, has noV plasticity or fluid qual es; and will tend to pack at the upper end of upright conduit section where the fel'is directed into the firebox by the top of the short upper section or hoed of the'. conduit. Furthermore if the top or hood of the conduit is raised to a height sm'licient to relieve any, pressure upon the rising column of fuel., the fuel column will then rise to a height whereby its upper portion willbreakaway of itsown weight and fall onto the distributing means in'gobs or un mi@ of fuel which' under certain conditions upp'lies fuel at a rate greater thanthe rate of combustion in th ebox and therefore nnconsunied volatile' matter is carried off 'by the stack, creating objec- 'the heavv dil-.ie to To overcome these cificnlties l have provided operative 1 iechanicalmeans which may be of any suitable co n, such,r for eX- ample,V screw or swig plunger or gate, which n elias are associated with the upper portion the n L conduit section d operate as a in nical feeder to de- Lce coal.

ieee. serial no. 292,447.

coal halts due to compressionof loose. coal taking place ahead of the point ofathe main feed screw and between it and the iront face of the elbow joining the main horizontal conduit section with the upright section. During this period of rest the feed screw orgate may, if desired, be actuated. Preferably this feeding means is synchronously operated from the motion of the stoker itself; orby a steam cylinder and piston, the admission and exhaust events of which are determined by the motion of the stoker.

My invention will be described( specifically and in detail in connection with the accompanying drawings which show three forms of the invention.

Fig. l is a fragmentary front to rear vertical sectional view showing a locomotive Stoker embodying one'form of the invention, only such parts of the locomotive and tender associated directly with the Stoker being dis'- closedr as are necessary to a full understand ing of the invention'. Y

Fig. 2 is a vertical sectional view taken on planes indicated by the section linesZ-?J in Fig. l and looking in the direction of the arrows at said lines.

Fig. 2a is an enlarged fragmentary plan view-illustrating certain of the connections betweenthe engine and the upper and lower fuel `feeding mechanisms.

Fig. 3 is a fragmentary section-taken from the same view-point as Fig. 2 but showing a niodiiication.

Fig. 3a is a fragmentary enlarged sectional view taken on a plane indicated by the section line 3a in Fig. 3 and looking in the direction of the arrows at said line. 1

Fig'. et is a fragmentary vertical sectional View corresponding to Fig. l but showing another modification.

Fig. 5 is a sectional view taken on the section line 5-5 in Fig. e and looking in the on planes indicated by the section lines 6 in Fig. 5 and looking downward.

Referring first to the form of the invention illustrated in Figs. 1 and 2, the frame of the locomotive is indicated generally at 7, said frame supporting a boiler having a backwall 8 and access to which is afforded through an aperture or fire door opening 10. Within the boiler is a grate 9 of suitable form. The locomotive cab-deck is indicated at 11. Below the plane of the cab-deck the coal or fuel material is moved from beneath the fuel bin floor 85 of the tender forward towards the locomotive boiler in a known manner as by the fuelefeeding device or conveyor screw 12 whichis arranged in the pipe or conduit 13 and delivered through the universal joint structure designated generally as 14 to the short, forward, conveyor screw section 15 which is operatively connected with the screw section 12. The screw or feeding device is suitably supported within the conduit.

The forward screw section 15 is positioned in the lower end or entrance portion of the elbow member 17 which is supported from the frame 7 by the element 18. The elbow member is flanged at 19 to receive and support the upwardly extending or vertically disposed housing member or conduit section 20. Said member 20, as will be seen, from Fig. 2, flares Youtward as it rises so that it is substantially elliptical in cross section. At the upper end of the member 2O and suitably connected therewith, is a short, horizontally disposed conduit section designated as a whole by the numeral 21 which in effect forms a continuation of the upwardly extending conduit.

If preferred, this section on element 21 may be made separate from and suitably connected with the vertical section 20. As shown herein, however, the sections 20 and 21 are integrally formed. The section 21 projects forward to the firing opening or if preferred partly through the opening and at the lower side thereof. The top part of the section 21 may be provided with a movable plate or door 23 hinged at 24 and preferably provided with suitable devices by which it may be secured in place. lVhen lifted or swung up about the hinge 24 as an axis, the door affords access to the section 21 and also to the upper part of the section 20. The top and side portions ofthe fire door opening not filled by the section or head 21 may be provided with a removable closure 26 of any desired construction.

Disposed in a suitable position in the lower portion of the fire door opening, there is preferably arranged a distributor head 27 provided with a diverging set of nozzles 28 for the distributing jets of steam or other fluid, the nozzle system being set above a distributing table or plate 29 which projects into the firing space of the boiler as is well understood. The distributor head 27 has, at its rear, as shown in Fig. 2, outwardly extending portions 30 with which are connected sets of steam pipes 31 individually controlled by valves 32. The parts heretofore described not being per se of my present invention, it is not deemed necessary to describe them in further detail. i

In carrying out the present form of the invention, there are provided supplementary feeding devices which, as shown in Figs; 1 and 2, comprise two short supplementary screwsY 33 horizontally disposed or if preferred at a slight 'angle therefrom and arranged to deliverA the fuel forward to the firing opening from the upper end of the member 20 and the section or head 21. The feed screws or mechanical feeding devices 33 as shown are arranged in parallelism and their shafts 34 are adapted to turn in suitable bearings 35 whichV may be secured to the upper-rear portion of the section 20. The outside end portionsof the screw shafts carry gears 36 which mesh respectively with intermeshing pinions 37 and 38 which also areysupported from the section 20. The pinion 38 is an` idler while the pinion 37 is rigid with a bevelled pinion 39 which meshes with a corresponding bevelled pinion 40 secured to the top of a vertically disposed shaft 41. The gear train above described is preferably housed within a sheet metal cover 42 which is secured by screws 43 to the section 20. The upper end portion of the shaft 41 may bear in theflower part of the cover which is suitably thickened at this point to afford a sufficient bearing surface.

The shaft 41, as it extends downward, is also directed toward the left as viewed in Fig. 2 so as to clear the conduit sections 20 and 17. At its lower end portion the shaft 41 carries a bevelled pinion 44 which meshes with a corresponding bevelled pinion 45 secured to the forward end of a horizontal shaft 46.

Any suitable source of power may be employed for communicating motion to the shaft 46. For example, as shown in the drawings, an engine indicated generally as 47 may be employed for this purpose, the piston rods 47a of said engine having connections to cranks 46a on the shaft 46. At its end opposite from the pinion 45 the shaft 46 is provided with a gimbal-joint connection indicated at 46?) with a shaft 48 for operating the main feed screw system 12, 15 with which the opposite end of the shaft is connected by means comprising the usual train of gears, 48a, 48", 12a. In other words, the engine, is a common source of power for the two sets of feeding devices, one for the main conduit section and the other for the upper conduit section.

rIhe shafts 48 and 46 are synchronized so that the rotation of the main screw 12 is '10 shaft 41. l

The screws 33 operate on the rising column of coal as it moves upward under impulse of xthe main screw feeding system through the conduit section 21, the effect of said Screws 33 '15 being to prevent packing or jamming of the coal and also to feed it positively forward in a. horizontal plane on to the table 29 where it is within the area affected by the distributing nozzles 28.

A modification of the screw feeding form of the invention is disclosed in Figs. 3 and 3EL wherein, as shown, the double feeding pair of supplementary feed screws is replaced by a single feed screw 50. This may be centrally disposed widthwise of the head or section 21 and made of somewhat larger size than the screws 33. The mechanical feeding device or screw is mounted on a shaft 51 which is rotatable in a bearing 52 suitably secured to the section 20, the end portion of said shaft outside the section 20 carrying a bevelled pinion 53 which meshes with a bevelled pinion 54 secured to the upper end of a vertical shaft 55. the lower end of which is connected to the engine or motor power in any suitable way as, for example, that described in connection with the Figs.1-2 construc-A tion.

The pinions 53 and 54 are protected by a housing or cover 56 secured'to the section 21 and which may provide a bearing for the upper portion of the shaft 55.f

Referring to the form of the invention shown in Figs. 4 to 6 inclusive, these figures illustrate the swingingrgate or plunger mechanism hereinbefore referred to. This is adapted to a Stoker syst-em corresponding with that hereinbefore described in connection with the Figs. 142 form of the invention so that the parts associated with the plunger mechanism need be only briefly referred to. The locomotive 7, the boiler leg 8, grate 9, fire door 10 and the screw feeding system 12, 15 operating in the conduit sections 13. 14, 17 below the cab-deck 11 are the same as in the prior construction.

Also within the fire space is arranged preferably a distributing table 29 associated with a jet system 28 on a distributor head 27 having end portions 30 connected to pipes 31 con trolled by valves 32. In other words, the steam jet 'distributing system of the first de-j scribed construction may be employed with the plunger gate construction.

Referring now to the parts that are diderently constructed in the Figs. 4-6 modification, the flanged upper end 19 of the elbow section 17 has fitted into it a lower end portion of a Vertical housing member 57 which resembles Oenerall the rior construction the lower end portion being cylindrical or circular in cross section and gradually flaring outward and being slightly flattened into elliptical form. The head, hood or short horizontally disposed portion 58 in which the housing portion 57 terminates, may bedetachable but, as shown, it is formed integrally with the housing. Positioned forward of the upwardly extending conduit 57 and within the lower portion of the fire door opening is disposed the jet distributing'system comprising the head 27. Thetop of the hood 58 may be provided with a hinged cover or closure 60l pivoted at 61 and affording access to the upper portion ,of the conduit system. The novel mechanical feeding means in this construction is in the form of a plunger or gate designated as a whole by the numeral 62. It comprises a` vertically disposed body portion 63, a lower curved or arcuate bottom portion 64 and strengthening or connecting webs 65 disposed at intervalsalong the gate.

The Igate 62 fits in an opening in the rear vertical wall of the conduit system, the lower edge and sides ofthe opening thereinbeing ribbed or thickened somewhat as indicated at 66 to co-operate closely with the opposing faces of the gate 62 whichv are adapted to slide lback and forth throughv the opening during swinging movements of the gate. The gate 62 is adapted to swing on an axle 67 having stationary bearings 68 and one end of said axle projects outward beyond its bearings and carries a crankarm 69 pivotally connected by a cross pin 70 with the upper end of a connecting member or link 71. vThe link 71 extends downward'and is offset sidewise as shown in Fig. 5, the lower end portion being forked or bifurcated. The bifurcations 72 are connected by a cross pin 73 which plays in a slot 74 formed at the outer end of one arm 75 of a lever member of the vfirst order having an oppositely eX- tending arm 76, the two arms being connected by an elongated pivot'portion 77 whereby they aremounted in offset relationship as shown in Fig. 6. The lever arm 76 carries f a pin 78 which (zo-operates with a cam slot 79 formed in a rotary cam member 80 which is connected through a gear system 81, 82 with a suitable source of power, such as an engine designated by the numeral 83, the piston rods 83a of said engine having connections` to cranks 82a on a shaft 82?) on one end of which the gear or pinion v82 is mounted. The opposite end of the shaft 82?) is suitably connected as by a gimbal-joint 82o Ywith the shaft 48 as inthe first described construction. A coiled spring 84 connected to the lever arm 75 tends constantly to move the connecting link 71 upward, maintaining the gate 62 in the full line (Fig. 4) or inoperative position wherein its body portion 63 is substantially aligned with the wall of the conduit section 57, leaving said section wholly open and unobstructed. The spring 84 assists to give a quick retractive movement or snap-back to the gate 62.

The cam element 79, is so adjusted and its relationship with the main screw feed so timed that the parts are synchronized to afford the most advantageous effect from the mechanical pusher or gate 62 which, through thel described train of connections, will be caused, at the proper time, automatically to swing inward on its axle 67, `to the dotted line position in Fig. 4, the effect being to push the coal inward through the hood or head 58 into the firing opening to the distributing means. The cam 79, 80 and the spring 84 co-operate to swing the gate member back to normal position, the result being to afford automatic pushing operat-ions of the gate at suitable intervals.

In view of what has heretofore been said as to the purposes and ladvantages of the present invention, it is not deemed necessary further to discuss these features. It will be observed that the invention provides positively operating mechanical means for feeding and forcing the coal or fuel material into the entrance to the boiler from the top of an upwardly advancing columnar mass of coal which receives moving impulses from below from the main screw feed system of the stoker contrivance. This system, Vof course, also operates as a positive mechanical feeding means so that the invention provides in effect two separate sets of positively operating mechanical feeding devices acting in separate sections of the conduit system. The two sets of feeding devices are connected by means entirely outside of the conduit system.

lVhile the feed screws 33 of the form of invention shown in Fig. 1 are shown and described as arranged in parallelism it is understood that these screws may be arranged in an angular or any position desirable that will cause the screws to deliver the fuel forwardly from the top of the upwardly extending conduit for the reasons set forth and come within the scope of my invention and that other constructions than those disclosed will readily suggest themselves for carrying out the invention, and changes may be made in the disclosed constructions, all without' departing from the invention.

I claim Y 1. In combination with a boiler irebox having a firing opening in the backwall thereof, a conduit curving from a lower portion to an upwardly extending portion, the upper end of said conduit terminating adjacent said firing opening, a distributor plate yextending within said firebox, a nozzle between said plate and saidA conduit, a conveying apparatus for delivering fuel to the lower portion of the conduit and forcing the fuel into its upwardly extending portion, and operative mechanical means including a spiral screw disposed in a substantially horizontal plane longitudinally of the firebox and extending across the upper end of the upwardly extending portion of said -conduit for delivering the fuel forwardly therefrom onto said plate in front of said nozzle.

2. In combination with a boiler iirebox having a firing opening in the baclrwall thereof, a conduit curving from a lower portion to an upwardly extending portion, the upper end of said conduit terminating adjacent said firing opening, a distributor plate extending within said firebox, a nozzle between said plate and said conduit, a conveying apparatus for delivering fuel to the lower portion of the conduit and forcing the fuel into its upwardly extending portion, operative mechanical means including a spiral screw disposed in a substantially horizontal plane longitudinally of the iirebox and extending across the upper end of the upwardly extending portion of said conduit,l for delivering the fuel forwardly therefrom'onto said plate in front of said nozzle, and a common source of power for actuating the conveying apparatus and said operative mechanical means.

3. In'combination with a boiler firebox having a firing opening in the backwall thereof, a conduit curving from a lower portion to an upwardly extending portion, the upper end of said` conduit terminating adjacent said firing opening, a` distributor plate extending within said firebox, a nozzle between said plate and said conduit, a conveying apparatus for delivering fuel to the lower portion of the conduit and forcing the fuel into its upwardly extending portion, operative mechanical means including a spiral screw disposed in a substantially horizontal plane longitudinally of the firebox and extending across the upper end of the upwardly extending portion of said conduit for delivering the fuel forwardly therefrom onto said plate in front of` said nozzle and means for synchronizing the operation of the two sets of delivery devices.

4. In combination with a. boiler firebox having a firing opening in the baclrwall thereof, a conduit curving from a lower portion to an upwardly extending-portion, the upper end of said conduit terminating adjacent said firing opening, a conveying apparatus for delivering fuel to the-lower portion of the conduit and forcing the fuel into its upwardly extending portion, fuel distributing means located forwardly from the upwardly extending portion of said conduit and extending within the firebox, and operative mechanical means including aplurality of spiral screws arranged vin parallelism longitudinally of the rebox extending across the upper end of the upwardly extending portion of said conduit for delivering the fuel forwardly therefrom on to said fuel distributing means.

5. In combination with a boiler firebox having a backwall with an opening therein, a fuel c bin, a conveying conduit extending forwardly from said fuel bin and having an upwardly curving portion on the outside of the rebox terminating in communication with said firing opening, a fuel distributing plate at said opening, screw means within said conduit terminating short of the upwardly curving portion for conveying fuel along said conduit and forcing it into the upwardly curving portion and operative mechanical means including a yplurality of rotating devices arranged in parallelism longitudinally of the firebox extending across the up-per end of the upwardly curving portion of the conduit for delivering the fuel forwardly therefrom on to said distributing plate, and means for scattering the fuel from the distributing plate to all parts of the irebox.

6. In a Stoker for a boiler, the combination of a conduit system comprising approximately parallel portions and an upwardly extending connecting portion, mechanical fuelfeeding devices in one parallel portion, separate mechanical rotary fuel-feeding devices arranged in parallelism in the other parallel portion and extending across the top of said connecting portion, and a jet distributing system receiving the fuel delivered by said rotary fuel feeding devices.

7. In a Stoker for a boiler, the combination of a conduit system comprising approximately parallel portions and an upwardly extending' connecting portion, mechanical fuel-feeding devices in one parallel portion, separate mechanical rotary fuel-feeding devices arranged in parallelism in the other parallel portion and extending across the top of said connecting portion, a et distributing system receiving the fuel delivered by said rotary fuel feeding devices, and a single actuating means for the sets of mechanical feeding devices independent of said jet system.

ANDREW M. HUNT. 

